In printing technology, scanning, exporting, and storing of color images in a printing network have started to become the standard features offered by digital multifunction devices. For such standard features, file size of an image document is an important factor. The file size of the image document that needs to be exported or stored is nowadays optimized using different available compression schemes and/or file formats. One of the popular compression schemes/file formats that are currently being offered is Mixed or Multiple Raster Content (MRC) file format. The MRC file format provides a way to achieve high image quality with small file size.
The MRC file format is generated by segmenting the image document (such as image file comprising mixed content such as text and pictorial/image data) into two or more layers including, for example, image layer (background layer) and text layer (foreground layer). Segmentation of the image document into the layers tends to improve compression of the image document, and also allows different compression methods to be applied to the different layers. For example, it is generally known in the art that MRC compression scheme implements JPEG compression to the image layer and JBIG2 compression to the text layer, in order to manipulate and compress the image document.
However, it is generally known that the JPEG compression is a lossy compression for digital images, particularly for those images produced by digital devices. Therefore, such lossy compression tends to produce artifacts that are visible while regeneration of the image layer (background layer). Accordingly, there is a need for a method of and a system for generating a MRC file format having lossless compression.